Tuning dial



June 13, 1933.

H. A. FLAMMER ET AL TUNING DIAL Filed Sept. 50, 1930 FIG/ FIG. 4

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EU u Will!!! INVENTORS: lzm ATTOP/VEY n the adjustable ortuning elen ientsef the radio member andthe spindle are eachj ournaled in p Patentedlune 13, 1933 um w-sml:

ficient in operation.

uselfon actuating the adjustable elements BATORIES, INCORFORK FE DkOF :nawaronxf, N; *Yi auconromirron orfiivnw 103x i i hppli catioii fil l l September-30, that f "I it i a s asmembers 12; is, 14am 151 th biigh a Thisihtentioh i-elates ta aming dials for;

radio apparatusandfth'e like on is the pro Vision of a'tuningi dial crane character which willbe simple, dheap to manufacture and et- According to this invention, a manually operablelknob is mounted on a spindle which isarrang-ed for rotating a pulley. Th s pulley is providedat its periphery -withaV shaped groove which friction-ally engages the beveled wages of two spring discs." These videdifor changing theresiliency of the pressure in the grooved pulley. The 1 hub a pair of parallel plates which areheldin spaced relation to each other byaplurallty of spacer l'nembers. One of the plates isprovided with an opening or Window through which appears a graduateddialfor indicat- 11 mg the position of the tuning elements with respect to an index member carried by one a of the p-lates,the indicator being in the form of a paper disc gluedonone of the spring discs and having marks for translating the Wave length of thesignals in terms of meters ;or kilocyclesorboth asdesired. l

Fig. 3 is a partial View of the spring discs assembly shown in an enlarged scale;

i Fig. 4 is a modification of the spring discs assembly; i a p i Fig. 5 is a portion of one of the discs shown in Fig. 4; and

l a Fig. 6 is another inodification of the spring discs assembly.

In Figs. 1, 2, 4 and 6 of the dI'aWingQIO and 11 are mountingplateswhich are heldin spaced relation With respect to each other by a are provided with peripheral beveled edgss which the screws 16, 17, 18 and 19 extend iii threaded engagementwith the plate 10. On

plates and 11 is journaled a hub 20: ?on

which a pair offspring discsZl g and 22 are securelyvmounted. Spring discs 21 andifQQ 25 and '26 arranged to register with a 23 is interposed between the discs "21 and grooved pulley 27 is determined as be hereinafter describedindetaijl. a y; j Grboved phlleyfl is itegrajlly farms plates 10 and 11 andionfolre end-bf this shaft ATE MFF CE A i;

y irbwhnnefirnamm or imwamr; mun EDWARD GQFRAGKEIQHOE i a ll 01mm: crry s mrmtrsmmnnnw YomnAssIGNoRs roBELL TELEPHONE LABO1 provided forf manually actuating the shaft 31 and the hub 20 through the engagement of spring discs, 21 and 22 withpulleyfl'l. On spring disc there is mounted a paperdial 28*Whichf cooperates with pointer 29 Eforj translating the movement of thediscs A the tun ng elements carried therebyin wai e lengthsatlwhichjthe radio signhls arereon I a panel 29 by means of {wane screws-such as 30jjand a screw 24:is providedfor opera tively connecting the adjustable shafth and the g cup of condenser plates &1, b and carried thereby to the 1ahiib {20. f

an operation, the rhov'ement of} shaft a eeperaaefi or knows is effect the spring discs 21 arid 22 thro and the pulleym27carriedthereby throirgh 1 ressurecondemn thegrooye\offpiilleyg The movement 0f discs 21 and 22, in mum 29, thisdiafbeinggraduatedforindicating tersor*lrilocyclesorboth asdesiijedi the Wave lengths of the radio signals ine- In the niodificationlshown"in[Fig.4 [the spring "discs '21 and are formed with cit:

cul'ar ridges 40 and 41 having their apexes provided with radial knurles or teeth as shown in Figs. 1 and 5. The disc 22 is mounted securely on the hub 20 and the disc 5 21 engages the threaded portion of the hub. In this arrangement the space between the peripheral edges of the discs 21 and'22 and therefore their contact pressure in the groove of pulleyc27 is adjusted by changing the distance atthe center of the discs, which is effected 'by'rotating the disc 21 on the threaded portion of hub 20, in order to decrease the distance at their centers and thereby force these discs to takea position as indigagement of the discs with the pulley 27 being effective to further assist in forcing the teeth at the apeXes of ridges in engagement with a considerable pressure and thus assuring the positive operation of the adjustable shaft '1 Similarly, in the modification shown in Fig. 6 thediscs 21 and 22 are each provided with circular ridges 40 and 41 disposed in abutting relation toeach other. i The disc 22 is mounted securely on the hub 20 and the disc 21 is securelymounted on one end of bushing 50 which is telescopically arranged in hub 20. The other endof this bushing is screw threaded-and is engaged by a nut screw 51 which is provided to movethe bushing 50 axially against the resiliency of the spring discs 21 and 22. In this modification a number of pins such as 52 are provided to prevent the relative movement of disc 21 with respect to disc 22 and the bushing 50 is provided with a longitudinally disposed slot 53 in which the set screw 24 extends to permit the engagement of this screw with the shaft 33.

In this arrangement the adjustment of the contact pressure between the resilient discs 21 and 22 and the grooved pulley 27 is effected by changing the space at the center of the discs through the tightening of nut screw 51, this adjustment being effective to increase thedistance between the peripheral edges of discs 21 and 22 and thus increase their pressure contact in the groove of pulley 27 as above. described in connection with the modification of Fig. 4:. 7

Applicants have discovered-that by changingv the diameter of spacer member 23 or its thickness or both, or providing the spring discs with ridges and an adjustment at their centers this furnished a means whereby a considerable pressure contact between the spring discs 20 and 21 and the sides .25 and 26 of groove pulley 27 can be obtained, thus making possible the positive operation of the dial against considerable load.

What is claimed is:

1. In a tuning dial, a pair of mounting plates, a driving shaft journaled in said 121mm Y- hai d. relaxer-r a Q l said cated by the dotted lines in Fig. 4, the en-' driving shaft between said plates, a pair of bevel edged spring discs, circular ridges in abutting relationship on said discs for maintaining said discs in spaced relation, a driven shaft journaled in said mounting plates for supporting said discs, and means on said driven shaft, cooperating with said circular ridges, for increasing the space between said discs. at their peripheries, by drawing the central portions of said discs towards each, other;

2. In a tuning dial, a pair of mounting plates, a driving shaft ournaled in said plates, a V -shaped pulley carried on said 'drivmg'shaft between said plates, a pair of bevel edged spring discs, circular ridges having serrations thereon, in abutting relationship on said discs, for maintaining said discs in spaced relation, a driven shaft journaled in said mounting plates for supporting said 

